Traditional techniques of periodontal therapy are frequently successful. However, there are often subjects and/or sites where treatment is unsuccessful. In most instances, we are uncertain why we succeed when we succeed and why we fail when we fail. Nor can we reliably predict which sites or subjects will constitute further treatment problems. Thus, the theme of this application will be to investigate the biological basis of periodontal treatment success or failure. Project 0005 will be concerned primarily with determining the effects of conventional periodontal therapy such as scaling and root planing (as well as surgery and tetracycline for some subjects) on clinical, microbiological and host risk indicators (factors) and the relationship of these factors to disease progression. 100 Black, 100 White and 100 Diabetic subjects will be recruited in Project A. They will be monitored pre-therapy and treated by scaling and root planing. Subjects who respond poorly to scaling will be treated with modified Widman flap surgery and tetracycline. This Project will indicate which risk indicators (factors) are changed by successful therapy and which factors are not changed in poor response subjects. Further, the study should indicate which factors might be used to characterize a subject who will not respond well to conventional therapies and whether certain therapies are more effective in certain racial, age, gender, or medical status groups. Project 0006 will be concerned with subjects who respond poorly to both scaling and root planing, and periodontal surgery with adjunctive systemically administered tetracycline. This Project relates to the "failure" side of the overall goals. Subjects in this Project will have a documented poor response to therapy and a new, extended series of tests will be employed to seek either microbial or host factors which might have led to the poor treatment response. If such factors can be identified, treatment will be adjusted to attempt to control the revealed factors. The emphasis in Project 0001 will be to develop new therapeutic or diagnostic procedures for the control of periodontal diseases. While Projects 0005 and 0006 emphasize an understanding of the biological basis of success or failure of current treatment procedures, Project 0001 looks to the future and attempts to foster novel therapies or diagnostics which may supplement existing procedures.